Technical Field
The present disclosure relates to a compensating hydrostatic bearing and regulator. More particularly, the present disclosure relates to an active compensating hydrostatic bearing and regulator.
Description of Related Art
Hydrostatic bearings play important roles in the precision manufacturing industry, such as automatic robotic arm, cutting machine, high speed machining tool and even astronomical telescope or wind generator. Excellent performances on mechanism locating, anti-vibration and high machining precision has made hydrostatic bearing a critical technology in the industry.
Hydrostatic bearings can be categorized by compensating types, such as constant pressure type or active compensating type. The constant pressure hydrostatic bearing is simpler so that can reduce the cost, but the response to an external loading is invariable since the flow resistance of the bearing is always constant, the characteristic causes the response to the external compression unfavorable.
The active compensating hydrostatic bearing can change the response to an external loading by adjusting the structure in short time for changing the inner pressure of the bearing, so that to overcome the disadvantage of the constant pressure hydrostatic bearing.
However, there are some problems need to be solved: to improve the response to an external loading, the active compensating hydrostatic bearing must adjust the inner pressure precisely and synchronously. That is, whether the inner pressure be adjusted properly or not will decide the properties of the active compensating hydrostatic bearing.
The active compensating hydrostatic bearing in prior art uses the external regulator to compensate the response according to an external loading, but this makes the compensation delayed because compensation liquid can't be input to or output from the bearing instantly. The asynchronous compensation causes the active compensating hydrostatic bearing in prior art poor to response to variable an external loading.
Another problem is that the accuracy of the active compensating hydrostatic bearing is demanding so parts in the bearing are usually combined together to avoid accumulated discrepancy. However, the manner is harmful to replace each of parts because all parts will be replaced wholly when anyone of them is fail, so the cost of the active compensating hydrostatic bearing stays high. And even so, it is still difficult to solve the problem of tolerance of each part fully.
Moreover, since the inner pressure of the active compensating hydrostatic bearing is changed according to an external loading, if the bearing is lack of buffer mechanism, the amplitude of compensating parts will be increased during adjusting the flow resistance. This leads the rigidity of bearing to decrease quickly with the rising loading and inferior stability.